Following the success of 634 a further order was placed through English Electric which included 42 more AEC 661Ts, 635 to 676. Of these 635 was built early and appeared on the English Electric stand at the first Commercial Motor Show at Earl's Court. It appears the opportunity was taken after that to make some more small refinements to the design.

Apart from 635, these vehicles entered service over a ten month period mainly in two blocks in July 1938 and May 1939. The former were for the conversion of the Wakefield Road service to Tong Cemetery and the latter for the long service to Crossflatts.

As can be seen, the batch had an eventful start with two overturning in the first two years. 639 also suffered bomb blast damage on Tyrrell Street on 31st August 1940. Despite this the whole batch gave great service to Bradford. The first were not withdrawn until 1955 (seventeen years service) and the last ones were in service until 1967 (twenty-nine years), lasting as long as the Tong Cemetery route for which they were bought.

To attain such long lives, many received new bodies, with 635-7/40/52 receiving Crossley bodies in 1952, 639 receiving a Northern Coachbuilders body from 618 in 1956. The biggest rebuilds were reserved for 638/51/54/55/59/64/66/74/77 which were given 27 foot long and 8 foot wide East Lancs bodies in 1956. Unsurprisingly these were the last survivors - the last English Electric-bodied example was withdrawn in 1959, 639 with its NCB body at the end of 1961 and the Crossley-bodied examples had all finished by the end of 1963.